Automated manufacturing systems that produce plastic articles have advanced to the point that they now generate significant amounts of plastic waste material at increasing rates. Other manufacturing and recycling systems also produce significant amounts of solid waste material, including plastic waste material. Many apparatus are known for comminuting waste material, such as plastic sheet material, into small, rather uniform particles or pieces that can be readily recycled or disposed of in an environmentally acceptable manner. For example, thermoforming machines mold articles that are heat formed from a sheet or web of plastic material as a pair of mating two-piece dies or molds impart an article geometry into a heated sheet of thermoformable plastic material to achieve a desired final shape. A typical thermoforming machine includes pairs of mating male and female dies, or molds, that are brought together on opposed sides of a preheated web of plastic material, during an operating cycle. The web of plastic material, including the formed articles, is then processed in a trim press where the articles are severed and removed from the web, leaving a skeleton web that is subsequently recycled in a comminuting apparatus.
U.S. Pat. No. 5,893,523 discloses one comminuting apparatus suitable for use in recycling a skeleton web of scrap material that is generated from a thermoforming machine and trim press of a thermoforming line. The comminuting apparatus includes a first material entrance and a second material entrance through which solid waste material is fed into the comminuting apparatus. The first material entrance is configured to receive a skeleton of plastic sheet material, whereas the second material entrance is configured to receive pieces of scrap and start-up formed web material that are typically hand-fed by an operator.
However, it is oftentimes difficult to hand-feed scrap and start-up material into the second material entrance, particularly when the comminuting apparatus is configured beneath a horizontal trim press where there is not a significant amount of clearance room. Additionally, the simultaneous delivery of waste material into two entrances can reduce efficiency by interfering with delivery of waste material at line speed from a trim press. Furthermore, the provision of such a comminuting apparatus beneath a horizontal trim press prevents operators from reaching the comminuting apparatus because typically such a configuration is shielded from operator interaction to prevent injuries and/or death. Accordingly, improvements are needed to enhance the ability to feed start-up and scrap material into a comminuting device while it is simultaneously configured for use in comminuting a skeleton web of plastic scrap material that exits a trim press.